Ionospheric absorption, typical ionization, conductivity, and possible synoptic heating parameters in the upper atmosphere

Abstract

Relations for the average energetic particle heating and the typical Hall and Pedersen conductances, as functions of the ground‐based HF radio absorption, are determined. Collis and coworkers used the geosynchronous GEOS 2 particle data to relate or “calibrate” the auroral absorption on the same magnetic field lines with five levels of D region ionization. These ionospheric models are related to a Chapman layer that extends these models into the E region. The average energetic particle heating is calculated for each of these models using recent expressions for the effective recombination coefficient. The corresponding height‐integrated heating rates are determined and related to the absorption with a quadratic expression. The average Hall and Pedersen conductivities are calculated for each of the nominal absorption ionospheric models. The corresponding height‐integrated conductances for night‐time conditions are determined and related to the absorption. Expressions for these conductances during disturbed sunlit conditions are also determined. These relations can be used in conjunction with simultaneous ground‐based riometric and magnetic observations to determine the average Hall and Pedersen currents and the Joule heating. The typical daily rate of temperature increase in the mesosphere for storm conditions is several 10 K for both the energetic particle and the Joule heating. The increasing importance of these parameters of the upper and middle atmospheres is discussed. It is proposed that northern hemisphere ionospheric, current, and heating synoptic models and parameters be investigated for use on a regular basis.